1. Field of the Invention
The present invention relates to a support structure, especially to a support structure with a foldable function.
2. Description of Related Art
A conventional flat monitor, such as a liquid crystal monitor, liquid crystal television or plasma television, has advantages of light in weight, thin in thickness and having no radiation, thereby being used to replace the CRT monitor which is heavy in weight and large in volume. As such, a support structure is a must-have accessory for the flat monitor. However, the flat monitor has a limitation of viewing angle, so at least a hinge structure is installed between the monitor and a base, thereby enabling the elevation angle of the flat monitor to be adjusted relative to the base.
However, the base is not equipped with functions of lifting or forwardly/backwardly moving the flat monitor. The skilled people in the art have developed an auxiliary connection member which is installed in parallel, e.g. end parts of two connection rods being respectively connected to a main hinge at the upper end of a connection unit and a base hinge at the lower end. Take the China Patent No. 1244852C (corresponding to the U.S. Pat. No. 6,822,857), issue on the 8th of Mar., 2006, titled in “Monitor improved in a tilting structure” for example; according to FIG. 5 disclosed in the patent, the components numbered as 100 and 110 are a pair of auxiliary connection members arranged in parallel, wherein a pair of auxiliary connection members at one lateral side of a connection unit, a main hinge and a base hinge jointly form a parallel four-bar linkage mechanism, such that the auxiliary connection members are enabled to convert the rotation motion of the connection unit relative to the base unit into the inclined motion of a monitor main body. In other words, when the height of the monitor main body is desired to be adjusted, and the connection unit inclines the monitor main body along the up/down direction, only the second and the third friction springs (sleeves) connected with the main rack would rotate around the third and the fourth hinges, thereby maintaining the original angle of the monitor main body during the displacement.
For a flat monitor manufacturer to reduce the volume during transportation, before the object to be supported, the connection unit and the base are packed, the above three have to be in a folding state for lowering the height to the minimum. Generally, a rotary state is formed between the connection unit and the main hinge of a conventional support structure, if the object to be supported, e.g. a flat monitor, is placed at a higher location while the support structure is in the unfolding state, and the flat monitor is desired to be rotated from a vertical state to a horizontal folding state, because the gravity center of the flat monitor is shifted, the support structure is more likely to fall or even cause damage to the flat monitor, therefore the inconvenience generated while the manufacturer or user processes the folding operation shall be improved.